Hydrates and, in particular, clathrate hydrates are understood to be crystalline water-based solids physically resembling ice, in which methane and other relatively small hydrocarbons are trapped. Methane hydrate deposits found on and beneath the ocean floor and in certain regions of permafrost constitute the majority of known natural gas reserves on the planet. In addition, hydrates of methane and other relatively small hydrocarbons form in producing petroleum wells and gas or oil pipelines. However, hydrate formation within producing wells and pipelines lead to solid plugs of ice with gas trapped within that occlude product flow when unmitigated.
Approximately 10 to 15% of production costs may be invested in the prevention of hydrate formation using technologies based on chemical additives (e.g., methanol, siloxane oligomers, poly-N-vinylpyrrolidone, and aluminum sulfate) and physical methods (e.g., high-frequency electromagnetic fields). However, when such preventative methods fail, the removal of a continuous hydrate plug, for example, in an offshore pipeline is costly. Mitigation strategies that are not reliant on chemical additives or external physical methods may offer an extraordinary cost savings to pipeline operations if an intrinsic property of the surfaces which contact petroleum, and therefore such hydrates, can be manipulated to reduce or eliminate the nucleation and/or adhesion of hydrates on such surfaces.
Providing organosilicone functionalization and coatings which decrease the adhesion of hydrates to these surfaces have been attempted. The hydrophobization of the metal surface has relied on, for example, reacting iron oxy-hydroxide functional groups present on the surface of carbon steels with trimethyl chlorosilane or chlorosiloxane oligomers, as well as the fluorine-substituted analogs of these reactants. While these strategies may result in surfaces that can be classified as hydrophobic relative to water, with water contact angles approaching 120°, these levels of hydrophobicity have been considered insufficient to inhibit hydrate nucleation, growth and adhesion on metal surfaces.